Abstract: AIM: To observe the role of endothelin antagonist bosentan that inhibits cultured neonatal mice cardiomyocyte from endothelin-1 (ET-1) induced cell hypertrophy.METHODS: Digested by trypsin, neonatal mice cardiomyocytes were isolated and cultured in 4 groups.With a group of regular culture cells as control, other three groups were respectively treated by bosentan 10 -8 mol·L ^-1, ET-1 10 ^-10 mol·L ^-1 andET-1 10 ^-10 mol·L ^-1 +bosentan 10 ^-8 mol·L ^-1 which were initially administered to the culture medium.The cell growing was observed carefully through micrography.72 hours later, the level of atrial natriuretic peptide (ANP) and ET-1 in the media of the 4 groups were determined by method of radioimmunoassay.RESULTS: The values of ANP in different groups were:6.46 ±0.38 μg·L ^-1 in control, 4.87 ±0.56 μg·L ^-1 in bosentan group, 13.60 ±1.12 μg·L ^-1 in ET-1 group and 9.42 ±0.58 μg·L ^-1 in ET-1 +bosentan group.Also by micrographic observation, endothelin induced cell hypertrophy was proved, and the hypertrophy could be reversed by bosentan.CONCLUSION: Endothelin induces hypertrophy of cultured neonatal mice cardiomyocytes, but it can be inhibited by endothelin antagonist of bosentan.

Key words: pharmacodynamics, endothelin, cardiomyocyte, bosentan